Required/optional ID flags should report better error messages

[jakedoublev]

1. The CLI should have intelligence to try to parse flag values that are expected to be UUIDs
2. The CLI should report better error messages contextualizing received/expected values when flags expect UUIDs but received non-UUID strings
3. BATS test

This error below was on attribute screate when --namespace-id was a namespace name and not an ID, and has caused confusion for users.

  ERROR    Failed to create attribute: rpc error: code = InvalidArgument desc = invalid input syntax for type uuid